Process of and apparatus for pressure casting



Sept. 29, 1925. 1,555,285

5. c. HOEY PROCESS OF AND APPARATUS FOR PRESSURE CASTING Filed July 14. 1923 WITNESSES: ENVENTOR .v' I Samue/C f/oey.

' ATTORNEY Patented Sept. 29, 1925.

UNITED STATES PATENT OFFICE.

SAMUEL C. HOEY, F WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING QOMPANY, A CORPORATION OF PENNSYLVANIA.

PROCESS OF AND APPARATUS FOR PRESSURE CASTING.

Application 'filed July 14, 1923. Serial No. 651,558.

T 0 all whom it may concern:

Be it known that I, SAMUEL C. HoEY, a citizen of the United States. and a resident of VVilkinsburg, in the county of Allegheny under pressure.

and State of Pennsylvania, have invented a new and useful Improvement in Processes of and Apparatus for Pressure Casting, of which the following is a specification.

My invention relates to a process of and an apparatus for casting metal bodies and more especially to the casting under pressure of the conductor members in the rotors of dynamo electric machines.

It is among the objects of my invention to provide an apparatus for casting metal bodies under pressure which shall be of simple, compact, mechanical construction, which shall be simple'to operate and adapted to the production of metal bodies in an expedient and inexpensive manner.

It is a further object of this invention to proy'ii'de a device which shall be capable of preventing the flaws in castings incident to the usual processes of casting molten metal It is well known that the pressure casting of molten metal as ordinarily practiced produces a body having blow-holes and fallen surfaces caused by cooling, especially at the portion of the casting farthest away from the charging port of the mold.

To overcome this diiiiculty, I propose to counteract the tendency of the material to shrink by'mechanical forces exerted in such manner and at such time as will compact the metal at the portion where shrinkage takes place, at the instant that the mold, is filled. By means of this process. the body produced is of uniform strength and the blow-holes are substantially eliminated so that the casting has a homogeneous structure throughout.

In the accompanying drawing constituting a part hereof and in which like reference characters designate like parts,

The single figure is a view, partially in vertical section and partially in elevation,

of a casting device embodying the princi-,

ples of my invention. 7 y

The device comprises a base 1, constituting a reservoir for molten metal, having operatively mounted therein a piston 2which is adapted to traverse in a vertical direction to raise the metal through a plurality duces acasting that has a of port holes 3 into the matrix 4 of a mold 5 which is secured to the top of the base 1. The mold 5 includes a base plate 6 and a clamping plate 7, the latter having an annular opening 8 adapted to receive a flanged ring 9 which is vertically movable therein. A piston 10 isconnected to suitable actuating means in co-operative alignment with the pressure ring 9 to effect a downward movement thereof when the piston is actuated.

A rotor 11 comprising a plurality of superposed sheet iron laminations is secured between the base plate 6 and clamping plate. 7 of the mold by means of a bolt 12 which has a screw thread engagement with thebase plate 6. The mold is formed to provide a plurality of annular spaces 13 and 14 'at the respective ends of the rotor 11, which is provided with slots or openings 15 communicating with the spaces 13 and 14. The metal occupying the slots 15 and the end spaces 13 and 14 constitutes the conductor bars and end rings, respectively, of the rotor when cast.

' The operation of the device is briefly as follows: The lower piston member 2 is actuated to exert a pressure on the molten metal in the reservoir causing it to rise and forcing it through the vertical ports 3 into the spaces 13, 14 and 15 in the rotor and the mold against the top clamping plate 7. When the mold is filled. the upper piston 10 is actuated downwardly after a predetermined period which is just previous to the complete setting or hardening of the metal while it is still somewhat plastic so that the pressure has the desired eflect in compressing the metal. This operation proomogeneous grain structure and further produces a well formed and completely filled body that may be cast to the desired dimensions, thereby v under pressure and exerting additional pressure on the casting'so for med before the metal is set. i t

2. A method of casting bodies which oomprises filling a mold with molten metal under pressure and exerting'an additional pressure on the casting so formed at a predetermined time after the body is cast.

3. Amethod of casting bodies which comprises filling a mold with molten metal under pressure and exerting a counteracting pressure on the casting so formed before the metal is set.

4. A method of casting bodies which comprises filling a mold with molten metal under pressure and then compressing the casting so formed before the metal is set.

5. A method of casting bodies which comprises filling a mold with molten metal under pressure and exerting pressure on the body so formed at the end opposite the chargin end.

6. A evice for casting bodies under pressure comprising a mold, a reservoirtherefor, a plurality of communicating ports between said mold and reservoir, a'pressure actuated piston in said reservoir, and another piston for the other end of said mold.

7. A device for casting bodies under pressure comprising a reservoir constituting a base for a mold mounted thereon, a plurality of pistons associated with said reservoir and mold and means for securing a rotor to be cast in the latter.

' 8. Adevice for casting bodies under pressure comprising a base, a mold mounted thereon, a reservoir comprising the inner chamber of said base, a plurality of communicating ports for said'mold and reservoir means for mounting a member to be cast in said mold, a piston for dischargingsaid reservoir and a piston for compacting the discharge in the said mold..

In testimony whereof, I have hereunto subscribed my name this 2nd day of July SAMUEL C. HOEY. 

